With the development of Information Technology (IT), living environments and residential environments have rapidly developed, so that energy and environmental problems have become issues. Therefore, the necessity for research and development into low-carbon green growth has been increasing. Although a lot of research has been carried out to meet this necessity, the research is in its early stage.
In particular, with the advent of the era in which each person is using one or more user terminals e.g., one or more mobile phones, noise and radio wave pollution caused by the neglectful use of user terminals and traffic accidents caused by communication while driving are frequently occurring in pubic places, such as an office, a classroom, a conference room, a theater, an airplane, an automobile, and a hospital. Accordingly, the demand for alternatives for providing etiquette and green environment services, e.g., the prevention of noise, the prevention of traffic accidents, the blocking of radio interference in important facilities, energy conservation based on the use of less battery power, and the like has been increasing.
A conventional alternative for providing a user terminal-related etiquette service in public places is configured to issue a broadcast to ask users to switch user terminals to vibration mode or ask users to turn off their user terminals. Another conventional alternative is based on a variety of research into the interruption and blocking of radio waves. However, the conventional alternative is problematic in that it is difficult to apply radio blocking to all user terminals in a public place, and in that it is difficult to rapidly release radio blocking in the event of an emergency, even when radio waves sent and received by all user terminals have been blocked.